<p>Oh, looks like you can take an ASE during IAP and have it not count towards the credit limit:</p>
<p>If you pass an Advanced Standing Exam during Orientation, your permanent record will show a grade of P (for Pass) and you may not enroll in the corresponding subject for credit. If you fail the exam, nothing will appear on your record and you are encouraged to enroll in the corresponding subject. Advanced Standing Exams taken during Orientation or IAP will not count towards the freshman credit limit. Exams taken during the fall and spring final examination periods will count towards the freshman credit limit.</p>
<p>from: [MIT</a> Class of 2012: Coming Up - Advanced Standing Examinations](<a href=“http://mit.edu/firstyear/2012/comingup/asexams.html]MIT”>http://mit.edu/firstyear/2012/comingup/asexams.html)</p>